Digital clocks based upon dual side band suppressed carrier modulation PublicDeposited

Descriptions

A method and apparatus are presented for generating suppressed carrier digital clock signals. These clock signals have the advantage of being broad band in nature and thus exhibiting lower power spectral density. Structures or systems utilizing such clock signals would be less likely to create electromagnetic noise of sufficient intensity to interfere with radio frequency systems and services.
The apparatus requires only digital logic devices, rather than the analog devices required for frequency- or phase-modulated spread spectrum clock generators. The method provides the opportunity to synchronously demodulate the clock, thus restoring the original narrow band clock signal where required.
The apparatus was implemented in a programmable gate array using 20 MHz and
33.33 MHz fundamental clocks. Measurements of the resulting electronic spectra and
clock jitter are reported.